Arrangement for locking a shaft to a machine member

ABSTRACT

An arrangement for locking a shaft or an axle to a machine member. The shaft has a cylindrical part which is intended to carry a bearing. The arrangement includes two expander sleeves which have a control internal shape and each of which is intended to be mounted on a respective end of the shaft of similar conical shape. The expander sleeves function as annular wedges with the apex of the wedge facing towards the cylindrical part of the shaft or axle and when tightening a nut are caused to expand against the machine member and lock the shaft. The shaft comprises an outer sleeve which faces the conically shaped end-parts, and a pin which is arranged coaxially with and within the sleeve and one end of which has an outwardly curved, mushroom-headed end-part whose radially inward surface is intended to abut an adjacent second expander sleeve, and the other end of which pin carries the nut with which the first and second expander sleeves are caused to expand into clamping contact with the machine member when tightening the nut.

The present invention relates to an arrangement for locking a shaft oran axle to a machine member, said shaft being intended to carry abearing on a central cylindrical part thereof. The arrangement includesfirst and second expander sleeves which have conical internal form andeach of which is located on a respective end of correspondingconfiguration on the shaft. The expander sleeves function as annularwedges with the apex of the wedge facing towards the cylindrical part ofthe shaft or axle and when tightened with the aid of tightening meanscan be caused to expand against the machine member and therewith lockthe shaft thereto.

An arrangement of this kind intended for locking a shaft or an axle tothe attachment lugs of a machine member is known from Swedish PublishedSpecification 435 953.

One drawback with this known locking arrangement is that locking iseffected through the medium of two nuts mounted on respective ends ofthe shaft and that when the shaft is located in a confined space, it isdifficult to reach the nuts in order to tighten the same. Accordingly,it is an object of the present invention to provide an improvedarrangement for locking a shaft or an axle to a machine member wheresolely one end of the shaft need be accessible in order to clamp or lockthe shaft to said machine member.

The inventive arrangement is characterised in that the shaft comprisesan outer sleeve, which presents the conically shaped end-parts, and apin which is arranged coaxially with and within the sleeve and one endof which has an outwardly curved, mushroom-headed end-part pandersleeve, and the other end of which pin carries the fastener means withwhich the expander sleeves are caused to expand into clamping contactwith the machine member.

The invention will now be described in more detail with reference to theaccompanying drawing, the single Figure of which illustrates a preferredembodiment of the invention in perspective and partly in section.

The illustrated embodiment of the inventive arrangement includes an axleor shaft which comprises an outer sleeve 1 and a pin 2 which extendswithin the sleeve 1 coaxially therewith. Screwed onto one end of the pin2 by means of screw threads 4 is a mushroom-headed end-part 3. The otherend of the pin 2, the outer end 5, is screw-threaded and carries atensioning nut 6 and a locking nut 7 which is located radially outwardsof the nut 6. The sleeve 1 has a central cylindrical part 8 onto whichthe inner race or like bearing-part 14 of a bearing 15 to be mounted onthe shaft can be press fitted. The illustrated embodiment of theinventive arrangement further includes two wedge-shaped expander sleeves9 and 10 which are caused to expand into engagement with a respectiveattachment lug 11 and 12 on the machine member, by tightening the nut 6.Disposed between the expander sleeve 9 and the tensioning nut 6 is aturnable washer or plate 13 which has a smooth side facing towards theexpander sleeve 9 in the manner illustrated.

The shaft is locked to the machine member in the following manner. Theend-part 3 is screwed onto the pin 2, whereafter the expander sleeve 10is fitted onto the sleeve 1 and the pin 2 is inserted through the axialbore of the sleeve 1. The expander sleeve 9 is then fitted onto theother end of the sleeve 1, whereafter the washer or plate 13 is fittedonto the pin 2 and the nut 6 is screwed onto the pin 2 and into abutmentwith the washer or plate 13. When tightening of the nut 6 is continued,the force generated thereby will cause the expander sleeves 9 and 10 toexpand so as to be pressed into recesses 16 and 17 in respective lugs 11and 12 and therewith lock the shaft to said lugs.

We claim:
 1. An arrangement for locking a shaft or an axle to a machinemember, said shaft being intended to carry a bearing on a centralcylindrical part (8) thereof, said arrangement comprising first andsecond expander sleeves (9, 10) which have a conical internal form andeach of which is intended to be mounted on a respective end of acorresponding configuration on the shaft, said expander sleeves (9, 10)functioning an annular wedges with the apex of the wedge facing towardsthe cylindrical part (8) of the shaft or axle and when tightened withthe aid of fastener and tightening means (6) are caused to expandagainst the machine member and therewith lock the shaft thereto, and theshaft comprising an outer sleeve (1) which presents the conically shapedend-parts, and a pin (2) which is arranged coaxially with and within theouter sleeve (1) and one end of which has an outwardly curved,mushroom-headed end-part (3) having a radially extending inward surfacethat is intended to abut said second expander sleeve, and the other end(5) of which pin (2) carries the fastener means (6) with which the firstand second expander sleeves (9, 10) are caused to expand into clampingcontact width the machine member and said mushroom-headed end-part beingdimensioned and arranged so as to facilitate the locking of the shaft tothe machine member solely through manipulation of the fastener andtightening means positioned at one end of said pin.
 2. An arrangementaccording to claim 1, further comprising a turnable washer or plate (13)positioned between said fastener and tightening means (6) and said firstexpander sleeve (9) and wherein said other end (5) of the pin (2) isscrew-threaded and wherein said fastener and tightening means (6)includes a tensioning nut screwed onto said other end.
 3. An arrangementaccording to claim 1, wherein the mushroom-headed end-part (3) is aseparate part which is screwed (4) onto the pin (2).
 4. An arrangementaccording to claim 2, further comprising a lock nut (7) which is screwedonto the pin (2) outwardly of the tensioning nut (6).
 5. An arrangementaccording to claim 2, wherein the mushroom-headed end-part (3) is aseparate part which is screwed (4) onto the pin (2).
 6. An arrangementas recited in claim 1 wherein said mushroom-headed end-part has anexterior surface with a portion of said exterior surface defining theinward surface abutting said second expander sleeve, said exteriorsurface being concave in cross-section such that said mushroom-headedend-part includes an axially elongated portion and a radially extendingend section.
 7. An arrangement as recited in claim 6 wherein said outersleeve includes a convex external end wall juxtaposed with respect tothe exterior surface of said mushroom-headed end-part.
 8. An arrangementas recited in claim 7 wherein the convex exterior end wall has acurvature corresponding with the curvature of the concavecross-sectioned exterior surface of said mushroom-headed end-part.
 9. Anarrangement as recited in claim 7 wherein the axially elongated portionof said mushroom-headed end-part has an inner end positioned axiallyinward of the external end wall of said outer sleeve and axially inwardof said second expander sleeve.
 10. An arrangement as recited in claim 1wherein said outer sleeve includes an external end wall adjacent theinward surface of said mushroom-headed end-part, and saidmushroom-headed end part including an axially elongated portion whichhas an inner end axially inward of the external end wall of said outersleeve and axially inward of said second expander sleeve.
 11. Anarrangement as recited in claim 10 wherein said mushroom-headed end-partincludes a head section extending radially outwardly from said axiallyelongated portion and having an axially inward wall surface of which aportion defines said inward surface abutting said second expander sleeveand said inward surface being axially external to said second expandersleeve and external to the machine member to which said outer sleeve isbeing fixed.
 12. An arrangement as recited in claim 1 wherein saidmushroom-headed end-part includes an exterior surface with a portiondefining said inward surface in contact with said second expandersleeve, said exterior surface being concave in cross-section and havingan axial portion extending inward of an external end of said outersleeve and in contact with said outer sleeve such that said outer sleeveis adapted to ride upon the concave exterior surface and further forcesaid expander sleeve against the machine member upon a tightening ofsaid fastener ends.
 13. An arrangement as recited in claim 1 furthercomprising a washer or plate positioned between the fastener means andhaving a peripheral edge extending radially outward to a greater extentthan that of said fastener means and an axially interior surface inabutment with said first expander sleeve (9) and adjacent external endof said outer sleeve, and the axially interior surface of said washer orplate being planer in a radial direction.